Combination-lock for electric circuits.



J. F. HENDRICKSON. COMBINATION-LOCK FORELECTRIC cmcuns.

. v APPLICATION FILED AUG.9, 1916. N 1mm. I PatentedSept. 11,191.

2 SHEETS-SHEET I.

J. F. HENDRICKSON.

COMBINATION LOOK FOR ELECTRIC CIRCUITS. APPLICATION man AUG.9. ms.

,invirnnsra ns ra rnnr enrich.

JOHN F. iruivnnroikzso v, or woLLAs'ro MASSACHUSETTS.

ooMBmATIoN-LocK For. ELECTRIC CIRCUITS.

ees/nee.

To all whom it mag concern: i

Be it known tlnitLJoiLN F; HENDnIoic son, of \Vollaston, in the county, of Norfolk audState of Massachusetts, have invented certain new and useful Improvements in Combination-Locks for Electric Circuits, of which the following is a specification.

This invention relates to means for preventing the-unauthorized use ofautomobiles unauthorized or accidental starting of the,

and othermechanisms or devices in which a.

current of electricity is;e1nployed,1and the OlU8fOb1QCi; of my invention is to provide an improved mechanism which,- for convenience of description, I term a lock, said lock having shiftable members which cooperate with correspondingly shiitablemembers of a removable device which 51 call a key, so that an electrical circuit may be completed when the key is inserted to operative position, and broken when the key is removed; Since the mechanism includes meansior making dii I ferent combinations that will be known only of the machine or boat is rendered diliicult.

The use of an individual electric motor for each machine in a machine-shop, is the modern idea. Sometimes a machinist wishes to leave. a piece of unfinished work in the mai chine. i'Vith my improved device included in the circuit oi the motor. for that machine,

machine during the absence olithe. operator froin that machine, can be madeperplexing and therefore improbable, The device is also useful in connection with the electric light circuit in a house orbuilding to enable the. owner, if going away, to interfere with the use of the current during his absence. My invention consists in the looking or preventing devices substantiallyfas hereinaf; ter described and claimed.

Of the accompanying drawings: liigure 1 is a diagrammatic view of the parts and some of the circuits as employed on an automobile. p

Specification bf Letters ratm.

box with its cover open. the dotted lines representing the outer fixed casing from.

which saidswitch box is partially with drawn-to either make wiring connections or. change the combination.

Fig. 8 represents an elevation partly in section. of the switch boX when in its normal position locked in its outer casing.

Fig. 9 represents a section on line 9 Fig. 8.

Fig. 10. represents a section on line l0-10 of Fig. 8, the cover being only partially illSGCl. 1

Fig. 11. is a plan view of the parts below the line 1 1ll of Fig. 8.

l igs. llaud 13 are detail views hereinafter, described.

Fig. i l is a perspective View of one of the duplex removablecontact pins of the switch box. i i

Simil ar reference characters indi ca te I Sllllllar parts in all of the views.

Referring first to Figs. 1 and 2, 20 indicates a support tor the devices comprising my invent on, which support may be the dash or foot board of an automobile. The tubular post 21 for the tubular steering;

, .95 in the usual inclined direction from said:

shaft 22 having the hand wheel extends support.

Suitably secured to post 21 is a casing 2% containing the mechanism for controlling.

the operation of a bolt 25. Said mechanism includes a magnet which, when the key, the

knob or head of which is indicated at 27, is

inserted the switch box whichis inclosed steered. Such insertion of the key, as hereinaiter described, also establishes acircuit Patented Sept. 11,1917.

Application filed August 9, 1316. Serial No.- 113,954.

for the spark plugs of the motor, or the starting rlevice, or both. chiefly to show the preferred relative pos 1 tions of the casings 2i and 26, so that the parts can be conveniently reached by the user of the car.

Mounted in the casing'2e'is a m'a'gnet 28,

preferably, although not necessarily, design'ed'to simiiltaneously attract two armatures 29 and 31 pivot-ally supported; at .30 and 32 respectively, and pivotally connected together" at 33'. The armature 29 carries'the bolt 25, and the arm'of said armature 29 is* longer than the-arm-of arinature 31 so that the latterwill have less throw than the former, in order that While armature 29 may have ample movement to permit bolt t0fully reacha firm locking position'as indicated in Figs. 4: and 5, yet armature'3l will not moveso faraway from the magnet as to fail to be operated by it to sh ft the parts to the positionsh'own in Fig: It is advisable to explain here that the bolt 25' moves from the" unlocking position of Fig. 3-to-the locking positionof" F igs. 4 and 5 by gravity, although, as is obvious, a spring might be" employed to aid grav1ty.. The

reason for employing three keeper holesw in shaft 22 is to enable the shaft to beleft locked with the steering Wheels straightor turn'ed sharply to the right or left. Vhen the combination key hereinafter described is inserted, the magnet 231s energized and there is a tendency to Withdraw the bolt.

Mounted to rock in" theupper end ofeasing 2l'isa studshaftiA having aknob 35 at its outer end and an arm 36 at its inner'end.

Said arm has a lateral-toe 37' and a shoulder 38 at its tip. A spring 398X6113S'2L constant tendency to hold the arm in" the position shown in Fig. 5 bearing against one] edge of the armatiire 29 which has; a projection as shown in Fig; 6 for' this purpose: WVhen the bolt is in locking position (Fig 5) theside =toe37 of thearm-36 overlies the edge of the armature and holds the bolt inthatpositi'on, even when the unlocking magnet 28- isenergized', until the user'manually operates knob 35 to rock shaft 34 to swing arm 36so that the toe 37 will release the armature and .permit the magnet, when it has been e11erg1Zed,- to a tt ract' the armature and lift'its bolt 25.- When the'u'ser' then releases the knob 35, after the magnet haswith dranfn the bolt, the arm 36 returns to the position shown" in F igi 5 but Withthe'sid'e 'toe3'7'be'low orunderlyin'g the armature'29 soas; to positively" hold the locking bolt 25 raised and in the unlocking position ofFig.

3 to avoid any liability of the steering shaft. becomi'n g accidentally locked during drivmg of the'car.

As is wellknown, a'rmatu'res sometimes becoineso' stuck to magnets as to refuse to leave them when desired,-even when the Fig; 15 is drawn magnet. is not energized. To insure the movement of the armature awayfrom the magnetji vhen the latter is inactive and it is desired that the bolt shall pass to locking position, I" provide the arm '36 With a lateral pin 4L0 (F ig,.,5),long. enough to act as a cam on the upper 'surface'of armature29 to push said.v armature away from the magnet When the aim'isswung to the left (Fig; 5)to release thetoe: 37:.from the underlying position above described, said pin 40 thus acting as a manually" o ei-atecpdvice-to' push the bolt to, or partially to, the 'locking pOSitiOII'Of' Fig-. 5.

The casing- 26 is flaredby: anysuitable means to J the rear sarifac'e of the support 20 I a in the combination of the lock-is to be effected. 1 I

The switch box; 41 has it'suhinged cover in two: sections 42;- 43; asindicated; in Figs. 7 and S. A's will lie-hereinafterexplained;-

when the switch" box is drawn out of' the casing 26'thr'ough the opening in the'support 20,5itcan be drawn only to; an eXt'ent" whiclrleaves the section 42 of 'th'e' cover still extending into" the'casing' 26. 'This is because-the section 42 ne'ver needs to be lifted exceptingwhen the-parts are-to be, or have been, very considerably dismembered; for the'purpose of fixing; the circuit connections. It is only the cover section 43' that ever needsto be raised for. the purpose of changing' the-combinations Within the box.

In the lower portionbfthe si'ir'itch box are sulating material," said bl'ocks being-so formed or cut away asrto providea space between inid portions" thereof"to admit the key and to contain? other parts presently described; Thespace for" the key 63, 65, isbes't indicated in]? igL 9; r

contained two*blbcks4a e 5- of suitablein- Mounted upon] thenpperblock aka (Fig. 7)

are four stri1')s"a6,4@7,48, L9 1of suitable conducting material, t'he'block 45 being formed with two series'of'holes SObetW'eeIi the two pairs of conducting strips as shown in Fig; 7. Said conducting strips extend from suit I able supporting studs 51"to four binding posts 52,53,554, seems-11 are supported by the. block 45: TWO shiftabl'e or! adjustable dupleipliigsior contact cl'e'i ice's are employed each comprising a pair'I'o'f pins'56, 57 '(Fig; 14) connected to a head 58 of insulating ma terial. The upper endof ea'ch'pin 56,157

projects outwardly so that when two of the duplex plugsshown in Fig. 1e are fitted in holes 50 as shown in Fig. 7 one of theconducting strips of each pair will be incon tact with the upper end of one pin and the other conducting strip of the pair Willbe in contact with the upper'end of the other pin. The conducting strips are resilient .so as to be spread slightly apart when the du- ;ple x plug is inserted, and then bear yieldingly against the pins 56, 57,.to preserve electrical contact. Referring now chiefly to Fig. 11 slldes 59 which may consist of brass] tubes, are

: mounted in ways 60 formed in theupper face be taken away by the-owner or-user of the machine or appliance employing the device,

when that machine or appliance is to beput out of commission, comprises a shank 63 having the knob or handle 27 hereinbefore mentioned. 1 The shank 63 has a series of holes Get adapted tohold a pair of pins 65 (F 8 and 11). so as to project from opposite sides of the shank, the pins being removably connected to said shank, as by screw threads or otherwise, so that either pin can be shifted to a different position longitudinally of the shank. The knob or head ,7

527 is rotatably connected. with the outcrcnd of the shank G3, and has a cam slot 66 into which a pin 67 projects from the shank (see .tdotted lines, Figs. 8 and 11) to cause the shank to shift in the direction of its length when the knob is turned ashereinafter described, the pins preventing the shank from turning. The knob orhead also has an outwardly projecting pin or detent' 68. adapted to be engaged behind a keeper flange (39 which is provided with a notch (Fig. 13) to enablesaid pin68 to be inserted behind thekeeperflange, said flange serving tokeep the key in its operative position after the head has beenturned. The space 70 behind the flange 69 forms a socket for the inner end of the knob or head, and. for the rotatiou ofthe pin 68. After the key is inserted, the knob is slightly turned so as to Without this device, or some equivalent carry the locking pin 68 aside from the notch 70, thereby locking the key in position.

therefor, the springs 61 would eject a key because said springs act on the tube slides 59, and the ends of said slides act on the pins of the key. The opposing faces of the insulating blocks are cut away orre:

cessed as best indicated in Fig. 9, to guide thepins of the key and prevent the shank of the key from being rotated after said shank and its pins are inserted.

' It maybe explained here that, through connections hereinafter described, the electric circuit to be complete must include the duplex plugs, leaf spring contacts 62, slides 51, and the key-shank (33 and its pins 65. "When the user or owner wishes to effect a certain combination, he sets the two duplex pins, one of which is shown in Fig. 14:, in the desired or preferred holes 50, which holes are indicated by consecutive numerals as shown in Fig. 7, and he correspondingly sets. or mounts the two pins 65 of the key so that they will be atjthe proper distance len thwise of the shank of the key to effect the pushing of the slides back to accurate position, when the key is inserted to its 1305i" tion of use as indicated in Fig. 11 to complete thecircuit just described. If the key is removed and in the pocket of the owner or. LlSQlYllOllilS'llllGll gone away, it is difli- .cult for anyoneto insert anythlng that Wlll not only act as a switch from one side to the other of the device but also push the slides to 'ust the no or ositions to cause person is likely to have time to do.

It is, of course, necessary that the owner or user shall be able to open the lid or cover l3 to make a change of the combination, and it is also desirable that no one else but the possessor of the key, and knowing the proper combination, shall be able to unlock the lid. or cover because, if this could be done, it would be quite easy to complete the circuit through the parts inside of the casing. I effect this lockingof the cover or lid by the following means:

Mounted upon an insulatingplate 73 securedto the inner side of the lid or cover section 43, is a magnet 74 (Figs. 7, S, 9, l0 and 12) having an armature 75 pivoted at 76 and having a spring 77 whichholds said armature against a stop 78 when there is no current through the magnet. Rising from block 45 is a keeper or catch 79 having a beveled side as shown in Fig. 12 so that when the lid is closed the armature will ride down said beveled portion and engage the shoulder of the catch under the influence of the springs 7 7 This is of course provided that the key is not in position to. complete the circuit. lVhenever the owner or user inserts the key and the circuit is completed ashereinafter described, the magnet attracts the armature 75 so as to release it from the keeper or catch 79, and enable the user to lift the cover sectionS, provided the switch box has been drawn out of the fixed casing 2-6 far enough to bring said cover section to the front-of the support 20; in other words, P'I'OVlClGClthG switch box has been drawn out from 1ts normaloperative position, Fig; 8,

to-the position shown in Fig. 7, to change,

5 the lock combination.

To prevent the switch box from being drawn out fronrthe -position shown-in Fig. 8, excepting by the person'having the key with the proper combination, I employ a lookingbolt 80 (Figs. 8 and-9) whiclris adapted to cooperate with a keeper Sit-which In ay comprlse-a spike or screw drivenlntothe support 20, andhaving its headin pos1-- tionto cotiperate, as a keeper, with said bolt 80." A spring 82, such=as apiece of spring wire having one endfitted to an aperturein'the bolt 89, and having its other end suit-- ably secured, serves to normally projectsaid bolt 80. The belt 80 has-an enlarged lower 2 0 end83 so located as to serve asan armature for one end of the magnet 74. lVhen the magnet 74: is energized, resulting from the insertion and operation ofthe combination key 63, 65, and the use of an QlGCtIlG currentthrough the circuitshereinafter described;

the magnet acts to withdraw'the bolt 80 so that'the user can then withdraw the switch box-from the position shown 111 Fig: 8, nearly out from the fixed casing 26', so that the 30 cover section 43 can be openedfor changing the combination if desired, by shifting the positions ofone orboth of the duplex plugs 56', 57 58; In order that theswitch box may not be drawn or movedoutwardlyunless by intention, I provide a suitable catch such as a'spring 8 1 (Fig. 8) secured at one end to the bottom of the switch 'bOX and bent to provide a detent shoulder 85, said spring H having a knob 86 at its front end. The spr1ngpasses through a vertical slot in the support 20, and through a slot'87 in-the' face plate 88' of the-switch box, which face plate is illustrated as carryingthekeepen flange 69 hereinbefore described When the 125 user has-inserted the combination'key to-operative'position, and the bolt 80 has been withdrawn bythe magnet 7 1, the switch box still cannot shift outwardly unless-the user grasps the knob 86, and lifts it -tocarrythe Bil detent' shoulder 85 above the bottom Y of the slot, and then pulls upon said knob to with draw the switch box;

switch box.

diate binding post 93, carried by the insulating'block45; A conductingstrip QfL CQH- nects-the"binding-posts 5e and These p arts ju -st described are diagrammatically. illustratect'in Fig; 2, in which figure the circuit connections which I will nowdescribe are illustr-ated":

A wire-95 connects'the-unagnet 28 with a battery 96 0i other source of electricity. wire 9? connects the battery with the inter inediate bindingpost 93- A-wire--98 con nects-the bindingpost-54 with-the magnet 28;: Vires 99and100connect the winding of the magnet-7 4 with the-iblades 89. A wire 101 connects the binding post-'54sl'with the spark plugs 102 of the: engine of. the motor. Awire l03 fronr said spark-plugs issuitably grounded. as at 104. A W1I8'105 connects 30 p the binding post 53' with=the magnets 106', from which a wire 10% is suitably grounded aeiosby con-nectingit to any s'uitable part of themachinet V. r V V The above circuits can be followed by 5 comparing Fig- 2 with: the other figures which show the details of;the different parts .of tlie apparatus. In E-ig. 1, which is semi- ,dia gr-a uuna'tic, I s have- -not attempted to indicate all of thecirc-u'its indicated in Flg; 2:

,Ih said Fig. 1 there are but three wires shown 'EtSflSS uing from "the SWltCllbOX WlllCli ,is containedin casing 26. O fthese, two of the wires 97 and 98, are supposedto bethe same"as th ose siinilarly indicated 1n Fig. 2, I

while the third wire 10 9 {leads to a devicev 110 which may be eithera magneto or the spark plugs- 0f a inotor, said device having a wire 111 leading to ground at 112. The said =Fig. '1' indicatesthat I may omit eitlier the magneto-or the spark plugconnections indicated in Fig. ln fact, I may omit, other connections sothatthe use'of the conibination-keywill control eitherthe lock 1 device for the steering post alone, or for the 105 magneto alone, orfor the spark plugs alone, orfor any other mechanism employing an electric current; i

In Fig: 8 I have not atteinpted to indicate whicli ofthe several wires there shown are thepjarticula-r circuit connections above de scribed. Itissufiicient to state that those- \VlI'BSWlliClf areconnec-tecb with 'parts oftheswitchbox pass through an' aperture 113 in the insulation blocks- 14 a1id:45,' and througha nipple 114 projecting downwardlyfrom said "switchbox V and then through a nipple 115 at the bottom of the narrow lower portion of theswitchbox casing 26t0 the other parts in circuit therewith. Sa-id narrow'portion:is indicated at 116,-and is provided for the purpose of ac-' commodating the portions 0f= the circuit wires so that said portions of the circuit wires can be' freely flexed back and forth when the switohbox isshiftedout or'in I will now describe the operation-of the mechanism as illustrated :5As has been. dc

' scribed the 'head 27 ofthlekey isrotatable 90, a blade 89 (since bothblades are then in i operator rotates the head of the key so as to on the shankand the shank is capableof moving in and out relatively to the switch box. 'Since the notch 70 in the keeper flange 69 (Fig. 13) is at thetop, while the space to permit the insertion of the key shank and its pins is horizontal, said key can only be inserted in a definite manner; that is, the pin 68 of the knob must roject upwardly to pass through the notch O. the pin 67 is at that end of the cam slot 66 which causes the key shank to be projected. Whenthe knob 27is rotated as far as the cam slot will permit, the pin 68, behind the flange 69, prevents longitudinal movement of the head while the key shank is retracted or drawn outwardly somewhat due to the action of cam slot 66 on the pin 67.WIn

brief, rotationof the head causes the shank and its contact pins to reciprocate slightly, or move in and out. When the key has been inserted as describedand the head rotated, the pin 68 (Fig. 8) passes over the surface of a curved spring strip117 (see also Fig. 13) which is so shaped that the head 27 will not be accidentally returned to initial position. H n ;If the car has a self starter then the bat thereof.

'Whenthe key is first inserted, its pins 65 engage the slides 59 and push them far tery 96 is to besupposed to be the battery enough back so that the leaf springs 62 contact'only with the rearmost pins 57 of the duplex plugs as shown in Fig. 2. This re sults in unlocking the steering wheel, be

cause a circuit isestablished through wire 95, magnet 28 'to act to withdraw bolt 25 as soon as the operator turns knob 35, wire 98, post 54, strip 458, the pin 57 of one duplex plug, a spring contact 62 and slide 59 on one side of the key, through the key and the slide 59 and spring contact 62 on the other side of the key, the pin 57 of the other duplex plug, strip 416, post'52, the strip 91, a jaw 8) and latch armature 7 5 (Fig.' 7 butun less a changeis to be made in the combination, or somerepalrs are to be made, no attent on is paid thereto. When, now, the

secure said key in place, such rotation, ow

ing to cam, slot 66, results in slightlywithdrawing the shank of the keyuntil the spring contacts bear against pins 56 in stead of pins 57. This is the position shown At this time out. Here the current passes from posth l through strip 94, post 55, strip 49, pin 56, through the key and spring contacts the same as before to strip 17, post 53, wire 105, magneto 106, and to a part of the machine which furnishesthe ground at 108. From 108 the circuitis completed through the metal of the machine including the point 112 (indicated as ground in Fig. 1), wire 111, device 110, wire 109, and any part of themechanism in casing 26 that willcomplete the circuitthrough wire 97 back to battery 96. At the same time a current is supplied from' post 5 1-, through wit-c1101 to the spark plugs 102 of the motor, through wire 103 to a part of the machine indicated at 104as ground, through the metal of themachine to either of the other gro'und connections 108 or 112, through Wires and n,

parts of the mechanism in casing 26 to post 'moval of the key results in instant breaking of all circuits, because the springs 61 (Fig. 11) act on slides 59 tocarry the leaf spring contacts 62 toward the front ofthe switch box, away from the pins of the duplex plugs.

Since the circuit through the magnet 7a upon by thespring, 77 to engage the catch 7 9 (Fig. 7 so that it is then impossible for any one, not having the key with the proper combination, to either complete the circuit or unlock or open the lid'orcover of the switch box, even if he could pull that switch box out from thefixed casing 26.

The device illustrated in the drawings is intended for light circuits such as would not injurethe magnets 28 and 74. If the de vice is made for a heavier current, such as to run the motor of a piece of machinery,

then as isobvious, the magnet 74 may be operated by means of shunt wiring. Of course under such clrcumstances there would be no magnet 28.

- I do not limit myself to the specific details ,of construction illustrated. For in- Istance, the number of different combinatlons that can be efl ected may be varied by-increasing or decreasing the number, of locations for the pins of the duplex plugs, and correspondingly decreasing or increasing the number of possible locations in the shank of the key for the pins 65 thereof.

'Having now described my invention what I I'claim is:

in Figs. 2 and 11, and the circuit fromthe g 1. Means for opposing unauthorized use of a motor vehicle employing electric connections for enabling it to be operated, said is broken, the latch armature 75 is acted Lcuit' iuseles's said device comprising, a, pair means comprising an adjustable terminal and a removable keyi having a, correspondingly adjustablemember ,for effecting the closing of the circuitthrough said connecti ons and terminal and through thekey.

2. rl device ior rendering an electric circuit useless, comprising a casing having an aperture, a pair of cooperating but normally separated adjustable contacts .Within lsaid casing, and a key removable. throughsaid aperture, said key havinganadjustable inemberadapted to bring said contactstovgeth'ei-i by msertron of saidfkey ln the casing to'ellect, the completion oi the circuit A- device (for rendering an ieleotric' {0111- shifting said contact away from the terminal nieinbeiu when. the said manually operable member-isremoved. j

5. Means for preventing completion of an electric circuit, comprising apairof terminals and a removable member adapted to complete acircuit which includes said, ter- 'minals, one-,of said terminals being adjustable to different operative positions, the rejniovable member having means adjustable to position to accord with the position ofsaid adjustable terminal. L

6. A device of the character described, comprising a casing havingvan opening for a key, and a key movable through said opening, said casing and key havingcorrespondingly adjustable circuit-controlling members relatively positioned to coact when the key is inplace.

1:7, A device of the character described, comprising a casing havingan openingfor a key, and a key movable through said opening, said casing andkey having correspondingly adj u stable circuit-controlling members relatively positioned to coact vliel the key is in place, means 'beingprovided for opposing accidental removal of the'key when insertedto operative;position; I f j j V 8; A device of the character described, comprising a casing containing a shiftable contact-member and having a cover adapted to beopenedto permit access for shifting said member. a key having a correspondinglyshilt'table contact member and adapted .to be inserted .in and removedffrorn leasing, .and me ns preventi1 ifgpe ng athecoverjwhen tlie keyiis removed.v V

-9. A device of V the, character described,

omprising a casing containing a shiiftable 1 c rcuit-controll ng member and having 4a cowl-adapted to be opelnedto perinitaccess Qfo shifting said member, a 1 key hav ng: a correspondingly shiftable {circuit-controlling member and adapted to be inserted in and removed from-said casinggg hlld :means. for ,:=opp,os ing. opening the cover when: thekey is removed, said means comprising a magnet, an armatulffi, catch codperating xvith said armature,; and circuit-connections including said ,Inagnet. (and the {shij 'table circuit-coni :trollinglm'eniber in'fthe casing; j i a 1 v 10. A device ofthe, ;character described comprisingfa cash" i..series offsockets, aicontact memberriior each lof, saidseries, said member being adapted toibe fi-ttedz to filly (lithe-sockets, a ,key radapted to. be: inserted, in and removed from said casing, ,said i; key: having 'a plurality ,of sockets, contact, members adaptedto. engage (said sockets of the. l ;ey,;.a;n d means iior como ,pleting, x circnitavlrenthe key is insertedto predetermined position.

gr h v ng a-rl' r li y 10 v I .device of H the character l-jdescribed, romprlslng I acasing: having; an opening @501 v a key, a'pair of conducting strips' -havinge sockets-mounted in; said casing, pins adapted to be mounted ,1 said socketsnslides movable n said caslng' and having members to, con- ,tact \v-itli ,.sa id ,pin Mandi, awkey m ovable V Qthro1 1gh the opening theica singfland:hath

jug slliifit'ab emeans fo aictuati ngs i lides- I: 12. device. of a the character described comprising erasing having an opening for .a; key,- a pair ofjcond "ngstripshhaving socketsmounted ,in said c g-pi s adapted .to be mountechin said jsocketgifslides movab1e1n said casingand hav ng m mbers to ioo contact with said pins, ,andga key movable through the opening of the. casing,- said key having a series of socketsfpin 'adapted/ ,v be mounted, in us'table; positions} in, said sockets, and means-Iron d operative pesition vvhen ns'ertec l.

. 13.,In a 1d'evfceof the, character described,

1 1 10, u inssth kf Jtwo pairs of" conductingjstrips; adjustable r conducting pins between said; strips, (slid- 1 mg ont c bpe ate vltll sald zPiIl Q and a key h aving adj ustablemernber 'to actuate f'sa'id sliding, contacts. I

, ,l lUIn afdevice of thejchagractei described, I

i o pa f Co din Jeeps,- adjus able conductingpinsbetween said stiips'sliding contacts to ,coepe ate; ith Said and, a conducting 1 key [hav ng a shank [provided with adjustable conducting pins to engage andshift said sliding contacts; j

15. In afdevice of the character idescribed,

llJWO pairs: ofconductinglstrips, adjustable n e eies P s e rsed r essl din contacts to cooperate with said pins, and a conducting key having a shank provided with adjustable conducting pins to engage and shift said sliding contacts, said key having a head rotatively and slidingly connected with its shank, and means whereby, when the key shank is in place and the head rotated, the shank will shift in the direction of it length.

16. In a device of the character described, a pair of conducting strips insulated from each other, a row of sockets between said strips, a duplex plug having two pins adapted to individually engage said strips, said pins being insulated from each other and adapted to fit said sockets, circuit connections with said strips, and means for selectively controlling a circuit through one or the other of said pins and strips.

In testimony whereof I have aflixed my signature.

JOHN F. HENDRICKSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. 0. 

